Yes, everything that either came with the shipping version of L4D2 for 360, was added after for free in an update (i.e. - bugfixes) or was available to purchase (i.e. - Cold Stream DLC) is all completely free on PC.

Yes, everything that either came with the shipping version of L4D2 for 360, was added after for free in an update (i.e. - bugfixes) or was available to purchase (i.e. - Cold Stream DLC) is all completely free on PC.